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2 years ago

A man walks forward on a bus. To a stationary observer, the bus moves east

Physics

1 answer:

yulyashka [42]2 years ago

5 0

Answer:

+19.5 m/s

Explanation:

In the reference frame of the stationary observer, the bus is moving east at 18 m/s, so its velocity is:

v = +18 m/s

Where we have taken east as positive direction.

In the reference frame of the bus, the man is moving 1.5 m/s also east, so its velocity is

$v_m' = +1.5 m/s$

Therefore, the velocity of the man in the reference frame of the stationary observer will be:

$v_m = v + v_m' = +18 + 1.5 = +19.5 m/s$

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You decide to work at a heart rate of 150 instead of 120. What area of F.I.T.T. did you change?

Rina8888 [55]

Key concepts

Heart rate

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Your heart is continuously beating to keep blood circulating throughout your body. Its rate changes depending on your activity level; it is lower while you are asleep and at rest and higher while you exercise—to supply your muscles with enough freshly oxygenated blood to keep the functioning at a high level. Because your heart is also a muscle, exercise, in turn, helps keep it healthy. The American Heart Association recommends that a person does exercise that is vigorous enough to raise their heart rate to their target heart-rate zone—50 percent to 85 percent of their maximum heart rate, which is 220 beats per minute (bpm) minus their age for adults—for at least 30 minutes on most days, or about 150 minutes a week in total. So for a 20-year-old, the maximum heart rate would be 200 bpm, with a target heart-rate zone of 100 to 170 bpm. (For those 19 or younger, target zones can vary more than they do for adults.)

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8 0

2 years ago

what velocity must a 1340kg car have in order to havw the same momentum as a 2680 kg truck traveling at a velocity of 15m/s to t

kykrilka [37]

Car with a mass of 1210 kg moving at a velocity of 51 m/s.
2. What velocity must a 1340 kg car have in order to have the same momentum as a 2680 kg truck traveling at a velocity of 15 m/s to the west? 3.0 X 10^1 m/s to the west.

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6 0

2 years ago

What type of equilibrium is guaranteed by each condition of equilibrium

Ostrovityanka [42]

Answer: Conditions for equilibrium require that the sum of all external forces acting on the body is zero (first condition of equilibrium), and the sum of all external torques from external forces is zero (second condition of equilibrium). These two conditions must be simultaneously satisfied in equilibrium

Explanation: Hope this helped

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2 years ago

Given the indices of refraction n1 and n2 of material 1 and material 2, respectively, rank these scenarios on the basis of the p

lisov135 [29]

Answer:

$c>d>f=a>b>e$

Explanation:

When a pair of medial has greater difference between the their individual refractive indices with respect to vacuum then it has a greater deviation between the refracted ray and the incident ray.

According to the Snell's law:

$\rm refractive\ index\ (n)=\frac{speed\ of\ light\ in\ the\ incident\ medium}{speed\ of\ light\ in\ the\ refracted\ medium}$

$n_1-n_2=1.33-1.00\\=0.33$

$n_2-n_1=1.46-1.33$

$=0.23$

$n_2-n_1=2.42-1.33\\=1.09$

$n_2-n_1=1.46-1.00\\=0.46$

$n_1-n_2=1.50-1.33\\=0.17$

$n_2-n_1=1.33-1.00\\=0.33$

$c>d>f=a>b>e$

5 0

2 years ago

Which one of the following statements concerning kinetic energy is true? a The kinetic energy of an object always has a positive

hodyreva [135]

a The kinetic energy of an object always has a positive value.

Explanation:

The kinetic energy of an object is the energy possessed by an object due to its motion, and it can be calculated as

$K=\frac{1}{2}mv^2$

where

m is the mass of the object

v is its speed

Let's now analyze each statement:

a The kinetic energy of an object always has a positive value. --> TRUE. In fact, the mass of the object is always positive, and the term $v^2$ is always positive as well, so the kinetic energy is always positive.

b The kinetic energy of an object is directly proportional to its speed. --> FALSE. Looking at the formula, we see that the kinetic energy is proportional to the square of the speed, $K\propto v^2$ .

c The kinetic energy of an object is expressed in watts. --> FALSE. Watts is the units for measuring power, while the kinetic energy is measured in Joules, the units for the energy.

d The kinetic energy of an object is a quantitative measure of its inertia. --> FALSE. The inertia of an object depends only on its mass, not on its speed.

e The kinetic energy of an object is always equal to the object’s potential energy. --> FALSE. The potential energy depends on the altitude from the ground, not from the speed, so the two energies can be different.

Learn more about kinetic energy:

brainly.com/question/6536722

#LearnwithBrainly

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2 years ago